It's dark in the void
by ThisIsMyNote
Summary: Catherine Watson's return from an MI6 placement in Grenada. And she needs a place to stay. So will John's good nature prevail, or will the deductions kill them all
1. Chapter 1

"Yes," said Dr John Watson. "Yes of course. I'm not sure how Sherlock will react but he's got a suspected Psychopath who hired a cabbie to murder him, so I think he probably will have more interesting matters to attend to."

"Oh, brilliant! How was your date with Jennifer last night?" His younger sister Catherine replied, chuckling.

"How did you... Oh I give up. You're bloody Sherlock all over again." John sighed, and put down the phone. It vibrated and flashed up a text from his sister.

**Don't you dare hang up on me EVER again. Oh, and by the way, go to Covent Gardens tonight. Much more romantic than Pizza Express.**

**CW**

"Bloody hell," said John to no one in particular. "Him and her together? Might as well have thrown myself off the roof of St Barts. They even end their texts the same way." He sighed and scratched his temple, turning to look in the mirror. There behind him, clad in black, stood Sherlock Holmes, doing what John had christened 'The Look'

"Oh, do enlighten me. Why are we having suicidal tendencies yet again." He sighed, and raised his hand to silence John, who opened his mouth to protest. "No, allow me. Your phone lies millimetres away, and you just sighed. Call from your sister. Twitch at the corner of your mouth. You aren't telling me something. Suicidal tendencies. She's coming here. But you wouldn't have offered Harriet help, so that must mean..."

"Yep," said John, smiling at the fact Sherlock had missed something else. "You missed her. Catherine. Cathy. Works for Mycroft, actually. Well, she's just been dismissed from her post in Grenada, at a bit of a loose end. So I said she could stay here. Because, you know Sherlock, that's what normal siblings do. They don't call each other arch enemies, and they don't see London as a battlefield. They do fight, but then they offer help. Go to the cinema, too, and out for dinner sometimes if they're feeling particularly kind. They definitely aren't like you and Mycroft..."

"Not many people are. In fact none are." Sherlock snapped. "Now, onto Catherine, or should I say Cathy. Works for MI6. Grenada. Dispute there in the eighties, something to do with communism. Not risky now, mainly touristic, got their first gold in 2012, generally respectable. But I highly doubt Catherine's there for a beach holiday. So maybe Myc... Oh! She's there to keep an eye on Santos and Nicaragua. Not sure why he brought her back. Soon, somebody's going to blow their top. Idiot. Always knew I was the smart one. But back to Catherine. She's younger than you, thirty one I'd guess, and she reminds you of me. But why? Is she rude? Arrogant? Dashingly handsome and smart? All of the above?"

John, who had been trying to interrupt for some time now, yelled

"Shut it Sherlock!" Sherlock raised an eyebrow in surprise "Yes, she's smart, she can deduce things like you. She reads people like a book and she can tell stuff from your tone of voice. She looks like you too, black hair and greyish eyes. And before you work this out from the rhythm of my snores or whatever it is you do, she and I don't talk too much, she's usually working. But she's better at people stuff. Even though she still hates them. She knows about you actually, not just from me, but also from Mycroft. She tends to organise his files. Including yours. She thinks you're a bit of an arse head really, leaving eyeballs in the fridge. I think she's forgotten..."

"The time she tried to microwave your goldfish's corpse when she was six. What?" Sherlock questioned as John glared at him. "Oh, sorry. Your story. I do forget this stuff. As you say, Mycroft and I didn't exactly have a normal childhood. When is she coming?"

John looked up from his latest update on his blog, the Blind Banker. Why on God's earth would Sherlock care?

"Erm... At about eight tomorrow morning. I'm out with Jennifer tonight, so I probably won't be up. I'm leaving you to greet her." John said. "See how much she needs a flat." He murmured to himself. "Now if you'll excuse me, I need to go and change."

***********The next morning************

"Sherlock!" Mrs Hudson called from the bottom of the stairs. "This lady at the door is getting quite impatient! She told me she was John's sister and needed to come and get settled in..."

"Yes Mrs Hudson..." Sherlock placed his violin down on the armchair and ambled towards the stairs and began to descend in his camel dressing gown. "Sorry Johann Sebastian," he murmured, "but you are just going to have to wait." He turned on his phone and checked his messages. John, Mycroft and an unknown number. He smiled and deleted Mycroft's. 'He never texts if he can talk,' Sherlock thought, his eyes flicking over John's reminders that Catherine would be arriving at about eightish, and looked at the message from the unknown number. It read:

**So. The famous Mr. Holmes. What an honour. I'm flattered. Now get your arse down here and open the door and I'll be even more so. I'm sure that Johann Sebastian won't mind.**

**CW**

He smirked and looked towards the old black door. Then double took and looked back at his phone. So she knew he couldn't bear to leave Bach. She was better than he thought.

**You better thank your lucky stars it wasn't Ludwig**

**CW **

Sherlock grinned and walked to the door.

It hadn't been a good flight.

Catherine Watson hated flying at the best of times, and, flying in Mycroft's high speed RAF jet, had just made her phobia a whole lot worse. They'd twisted and turned, as if they were playing tag with the ocean, and she began to regret the large breakfast she'd had that morning.

"Not used to this, are you Miss Watson?" Mycroft teased from the seat behind. "Not used to the 'high life' it may seem…"

"I distinctly remember having twenty four hours to book my own flight on my way out here," Cathy snapped back through gritted teeth. "How's the diet, Mycroft?"

He dismissed her comment with a wave of the hand.

"Oh, Sherlock is going to love you! You just stole his trademark comment. You're lodging with him and John. I hope you like toenails in the fridge." And with that, Mycroft turned over, signifying the end of the conversation.

Catherine sighed at this comment. She hadn't realised John had a flatmate. He'd 'forgotten' to mention, she was sure. She made use of some of what Mycroft called 'basic luxuries' and emailed John.

**I'm sorry. You have a flatmate? Who'd want to lodge with you?**

She sighed. Looked like John's lying was improving more the longer she was away. Opening MI6's notable files, she searched 'Sherlock Holmes'.

_Name: Sherlock Holmes_

_Age: 35_

_Residence: 221B Baker St._

_Younger brother of Mycroft Holmes. Highly functioning sociopath. Possibly suffering from Schizoid Personality Disorder (SPD). Highly skilled in deductions. Consulting detective. Has an assistant by the name of John Watson (Retired army doctor) Unidentified enemy, calls self Moriarty._

Her grey eyes scanned the report. But they only picked up one word. Moriarty...


	2. Chapter 2

Sherlock Holmes reached for the doorknob of 221B Baker St. He still wasn't sure when he had agreed to this, but John had promised, and he could tell from the way that John scratched his head that he wasn't lying. He wondered what Catherine would be like. He'd tried to get access to the MI6 files, but had been emailed furiously by Mycroft multiple times and had red 'ACCESS DENIED' imprinted across his Retina screen. From how John had spoken about her, she was his little pet, and he was protective of her, even though they bickered a lot. John evidently didn't approve of her placements with MI6, and he stopped talking to her when she became aware of his opinions. She needs help, she calls John. He wondered what it'd be like to call Mycroft for help. Nah, he'd rather go to Moriarty, whoever he was. Neither of them seemed to speak to Harriet, perhaps she was like a family disappointment. There was another impatient rapping at the door. Sherlock Holmes sighed, and opened the door.

Outside the door stood a woman of average height. She had dark brown hair and grey eyes, and was wearing a coat that quite obviously was bought by Mycroft. He looked at her further. He could tell that she was stressed out, and that she'd had a phobia of flying which Mycroft had recently worsened. She looked up to John, but had little respect for Harry and her decisions regarding alcohol. He sighed and smiled in what he hoped was a warm way.

"Come in. John's still at Justine's, so I'll get Mrs Hudson to make you tea." He turned and yelled at the closed door of 221A. "MRS HUDSON!" Mrs Hudson came scuttling out of her flat, and glanced at the woman standing in the doorway.

"That'll be tea, won't it Sherlock." She said with a sigh, before turning to Catherine. "Just this once dear, I'm not your housekeeper." Catherine looked at Mrs Hudson, and asked

"Did Sherlock really aid your husband's conviction?" She asked and watched Mrs Hudson sigh.

"There are two of you? I hope you don't give my bloody wall another battering, young man, so you better watch out. Go watch the crime on the telly, surely that'll keep you occupied. And if it doesn't," Mrs Hudson hesitated "call that nice policeman. I'm sure he can find you a nice serial killer… But I'll go make your tea, shall I?" And with that, Mrs Hudson scuttled towards her kitchen, only to be stopped when Sherlock called after her

"Don't forget the biscuits!" She turned and gave him a look.

"Not your housekeeper!" She said to herself as she bumbled away.

Catherine looked up at Sherlock Holmes and made a mental note of what she saw in comparison to MI6's files. He really wasn't that different, aside from the fact that he was more arse-like in reality and he had little (to no) respect. She wanted to say something, but, deciding that he was allowing her to lodge at his house, she resorted to glaring at his back as he climbed the stairs to 221B. He wore a long black winter coat with the collar turned up, concealing a blue scarf. She wore her collar turned up too, although that was probably for very different reasons, ones which she had trained herself to make indeductable, hidden in the darkest part of her that not even John knew about. His hair was black, and curly, though his MI6 profile showed him with not much hair at all. Catherine decided to check with Mycroft about how regularly he updated the files. She winced as he turned and looked over her, taking in all they could from her hostile glare. He turned fully around, he was at the top of the stairs now, and gave her a glare that (if possible) was colder than her own.

"How did you know I don't play Ludwig?" he demanded of her. "How do you know I even play?" Catherine glared up at him; he was a good deal taller than her, which gave her the look of an angry otter.

"I have a name, Sherlock Holmes. And this name likes to be respected. Now, if you'll _kindly _show me the way to my room, I have assassins to attend to." She gave Sherlock a large, fake smile before murmuring to herself "and Moriarty to keep of my trail…" And with that, she smiled and made her way towards where her bags were waiting.

"and Moriarty to keep of my trail…" Sherlock Holmes switched into thinking mode when she said this. So Catherine Jane Watson knew Moriarty. Things were going to get interesting.

And Jim switched off his screen and laughed.

"It's showtime Carl…"


End file.
